Issue with slotted hole dimension
Issue with slotted hole dimension
(OP)
I am having a field issue with slotted hole dimensions. This is for base plate related to a 20 ft light post in a parking lot
The anchors are 1 in dia, so I specified 1 1/16 in x 2.5 in slotted holes.
By mistake filed drilled 1 1/4 x 2.5 and now they are asking me if I can buy them off. They are worried about schedule impact etc.
What do guys think.
The anchors are 1 in dia, so I specified 1 1/16 in x 2.5 in slotted holes.
By mistake filed drilled 1 1/4 x 2.5 and now they are asking me if I can buy them off. They are worried about schedule impact etc.
What do guys think.






RE: Issue with slotted hole dimension
The "accident" may have been a very deliberate attempt to introduce some field tolerance.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Issue with slotted hole dimension
It's not uncommon to oversize (and by this, I don't just mean OVS holes) anchor bolt hole patterns to allow for placing tolerance. Typically, the contractor will install large plate washers that are field welded to the base plate so the bolt can still be considered a bearing connection.
If it doesn't adversely affect your structure, and they're willing to provide and field weld the plate washers, I don't see a reason for alarm.
RE: Issue with slotted hole dimension
//This is similar to standard oversized base plate holes//
But standard oversize holes are only 1/16 in larger than ordinary hole right? this is 3/16 in larger. (please correct me if I am wrong)
//The "accident" may have been a very deliberate attempt to introduce some field tolerance. //
I think u nailed it, they haven't paid any attention to detail. As this is simple post they took it for granted and now asking me to bless it.
When you say decent washer, does 5/16 in washer suffice? I think code requires 5/16 in (I don't have code handy, I am at site)
RE: Issue with slotted hole dimension
yes I considered the impact of slotting in the design, I was just concerned about larger than code prescribed holes.
I will mention about welding the field washer. they will provide field welded washers
RE: Issue with slotted hole dimension
I don't think so: Link
Check this out: Link
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Issue with slotted hole dimension
tightened down provide some welds on the four sides of the plates at each bolt.
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RE: Issue with slotted hole dimension
As for the size of your washer, that depends on the forces you're trying to transmit -- you'll have to run a quick calc for the washer and weld. Before I would go too far trying to optimize the thickness though, I'd check with your contractor. They may have a pile of those 1/2" or 3/4" formwork plate washers laying around that they'd be just as happy to use.
RE: Issue with slotted hole dimension
RE: Issue with slotted hole dimension
Thank you all for your inputs and time. Really helpful :)
RE: Issue with slotted hole dimension
RE: Issue with slotted hole dimension
That's a good legal point and may be true if the issue is major and there is no possible fix either through field mods or engg judgment.
Also as you know engineering and construction work together, I just cannot burn them for a small discrepancy like this.
In this case by talking to you guys through this forum I realized that its not worth to make a big fuss. This slips the whole schedule and as holiday week end is coming up, this can slide for couple of weeks